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Commit be77196b authored by Cyrill Gorcunov's avatar Cyrill Gorcunov Committed by Linus Torvalds
Browse files

fs, notify: add procfs fdinfo helper 



This allow us to print out fsnotify details such as watchee inode, device,
mask and optionally a file handle.

For inotify objects if kernel compiled with exportfs support the output
will be

 | pos:	0
 | flags:	02000000
 | inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:7e9e0000640d1b6d
 | inotify wd:2 ino:a111 sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:11a1000020542153
 | inotify wd:1 ino:6b149 sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:49b1060023552153

If kernel compiled without exportfs support, the file handle
won't be provided but inode and device only.

 | pos:	0
 | flags:	02000000
 | inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0
 | inotify wd:2 ino:a111 sdev:800013 mask:800afce ignored_mask:0
 | inotify wd:1 ino:6b149 sdev:800013 mask:800afce ignored_mask:0

For fanotify the output is like

 | pos:	0
 | flags:	04002
 | fanotify flags:10 event-flags:0
 | fanotify mnt_id:12 mask:3b ignored_mask:0
 | fanotify ino:50205 sdev:800013 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:05020500fb1d47e7

To minimize impact on general fsnotify code the new functionality
is gathered in fs/notify/fdinfo.c file.

Signed-off-by: default avatarCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: default avatarPavel Emelyanov <xemul@parallels.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 711c7bf9

fs/notify/Makefile

+1 −1
Original line number Diff line number Diff line 
obj-$(CONFIG_FSNOTIFY)		+= fsnotify.o notification.o group.o inode_mark.o \

				   mark.o vfsmount_mark.o

				   mark.o vfsmount_mark.o fdinfo.o



obj-y			+= dnotify/

obj-y			+= inotify/

fs/notify/fanotify/fanotify_user.c

+2 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <asm/ioctls.h>



#include "../../mount.h"

#include "../fdinfo.h"



#define FANOTIFY_DEFAULT_MAX_EVENTS	16384

#define FANOTIFY_DEFAULT_MAX_MARKS	8192
@@ -428,6 +429,7 @@ static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long ar 
}



static const struct file_operations fanotify_fops = {

	.show_fdinfo	= fanotify_show_fdinfo,

	.poll		= fanotify_poll,

	.read		= fanotify_read,

	.write		= fanotify_write,

fs/notify/fdinfo.c

0 → 100644
+175 −0
Original line number Diff line number Diff line 
#include <linux/file.h>

#include <linux/fs.h>

#include <linux/fsnotify_backend.h>

#include <linux/idr.h>

#include <linux/init.h>

#include <linux/inotify.h>

#include <linux/fanotify.h>

#include <linux/kernel.h>

#include <linux/namei.h>

#include <linux/sched.h>

#include <linux/types.h>

#include <linux/seq_file.h>

#include <linux/proc_fs.h>

#include <linux/exportfs.h>



#include "inotify/inotify.h"

#include "../fs/mount.h"



#if defined(CONFIG_PROC_FS)



#if defined(CONFIG_INOTIFY_USER) || defined(CONFIG_FANOTIFY)



static int show_fdinfo(struct seq_file *m, struct file *f,

		       int (*show)(struct seq_file *m, struct fsnotify_mark *mark))

{

	struct fsnotify_group *group = f->private_data;

	struct fsnotify_mark *mark;

	int ret = 0;



	spin_lock(&group->mark_lock);

	list_for_each_entry(mark, &group->marks_list, g_list) {

		ret = show(m, mark);

		if (ret)

			break;

	}

	spin_unlock(&group->mark_lock);

	return ret;

}



#if defined(CONFIG_EXPORTFS)

static int show_mark_fhandle(struct seq_file *m, struct inode *inode)

{

	struct {

		struct file_handle handle;

		u8 pad[64];

	} f;

	int size, ret, i;



	f.handle.handle_bytes = sizeof(f.pad);

	size = f.handle.handle_bytes >> 2;



	ret = exportfs_encode_inode_fh(inode, (struct fid *)f.handle.f_handle, &size, 0);

	if ((ret == 255) || (ret == -ENOSPC)) {

		WARN_ONCE(1, "Can't encode file handler for inotify: %d\n", ret);

		return 0;

	}



	f.handle.handle_type = ret;

	f.handle.handle_bytes = size * sizeof(u32);



	ret = seq_printf(m, "fhandle-bytes:%x fhandle-type:%x f_handle:",

			 f.handle.handle_bytes, f.handle.handle_type);



	for (i = 0; i < f.handle.handle_bytes; i++)

		ret |= seq_printf(m, "%02x", (int)f.handle.f_handle[i]);



	return ret;

}

#else

static int show_mark_fhandle(struct seq_file *m, struct inode *inode)

{

	return 0;

}

#endif



#ifdef CONFIG_INOTIFY_USER



static int inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)

{

	struct inotify_inode_mark *inode_mark;

	struct inode *inode;

	int ret = 0;



	if (!(mark->flags & (FSNOTIFY_MARK_FLAG_ALIVE | FSNOTIFY_MARK_FLAG_INODE)))

		return 0;



	inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);

	inode = igrab(mark->i.inode);

	if (inode) {

		ret = seq_printf(m, "inotify wd:%x ino:%lx sdev:%x "

				 "mask:%x ignored_mask:%x ",

				 inode_mark->wd, inode->i_ino,

				 inode->i_sb->s_dev,

				 mark->mask, mark->ignored_mask);

		ret |= show_mark_fhandle(m, inode);

		ret |= seq_putc(m, '\n');

		iput(inode);

	}



	return ret;

}



int inotify_show_fdinfo(struct seq_file *m, struct file *f)

{

	return show_fdinfo(m, f, inotify_fdinfo);

}



#endif /* CONFIG_INOTIFY_USER */



#ifdef CONFIG_FANOTIFY



static int fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)

{

	struct inode *inode;

	int ret = 0;



	if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE))

		return 0;



	if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) {

		inode = igrab(mark->i.inode);

		if (!inode)

			goto out;

		ret = seq_printf(m, "fanotify ino:%lx sdev:%x "

				 "mask:%x ignored_mask:%x ",

				 inode->i_ino, inode->i_sb->s_dev,

				 mark->mask, mark->ignored_mask);

		ret |= show_mark_fhandle(m, inode);

		ret |= seq_putc(m, '\n');

		iput(inode);

	} else if (mark->flags & FSNOTIFY_MARK_FLAG_VFSMOUNT) {

		struct mount *mnt = real_mount(mark->m.mnt);



		ret = seq_printf(m, "fanotify mnt_id:%x mask:%x "

				 "ignored_mask:%x\n",

				 mnt->mnt_id, mark->mask, mark->ignored_mask);

	}

out:

	return ret;

}



int fanotify_show_fdinfo(struct seq_file *m, struct file *f)

{

	struct fsnotify_group *group = f->private_data;

	unsigned int flags = 0;



	switch (group->priority) {

	case FS_PRIO_0:

		flags |= FAN_CLASS_NOTIF;

		break;

	case FS_PRIO_1:

		flags |= FAN_CLASS_CONTENT;

		break;

	case FS_PRIO_2:

		flags |= FAN_CLASS_PRE_CONTENT;

		break;

	}



	if (group->max_events == UINT_MAX)

		flags |= FAN_UNLIMITED_QUEUE;



	if (group->fanotify_data.max_marks == UINT_MAX)

		flags |= FAN_UNLIMITED_MARKS;



	seq_printf(m, "fanotify flags:%x event-flags:%x\n",

		   flags, group->fanotify_data.f_flags);



	return show_fdinfo(m, f, fanotify_fdinfo);

}



#endif /* CONFIG_FANOTIFY */



#endif /* CONFIG_INOTIFY_USER || CONFIG_FANOTIFY */



#endif /* CONFIG_PROC_FS */

fs/notify/fdinfo.h

0 → 100644
+27 −0
Original line number Diff line number Diff line 
#ifndef __FSNOTIFY_FDINFO_H__

#define __FSNOTIFY_FDINFO_H__



#include <linux/errno.h>

#include <linux/proc_fs.h>



struct seq_file;

struct file;



#ifdef CONFIG_PROC_FS



#ifdef CONFIG_INOTIFY_USER

extern int inotify_show_fdinfo(struct seq_file *m, struct file *f);

#endif



#ifdef CONFIG_FANOTIFY

extern int fanotify_show_fdinfo(struct seq_file *m, struct file *f);

#endif



#else /* CONFIG_PROC_FS */



#define inotify_show_fdinfo	NULL

#define fanotify_show_fdinfo	NULL



#endif /* CONFIG_PROC_FS */



#endif /* __FSNOTIFY_FDINFO_H__ */

fs/notify/inotify/inotify_user.c

+2 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 
#include <linux/wait.h>



#include "inotify.h"

#include "../fdinfo.h"



#include <asm/ioctls.h>
@@ -335,6 +336,7 @@ static long inotify_ioctl(struct file *file, unsigned int cmd, 
}



static const struct file_operations inotify_fops = {

	.show_fdinfo	= inotify_show_fdinfo,

	.poll		= inotify_poll,

	.read		= inotify_read,

	.fasync		= inotify_fasync,